My 4 year old has a white rash not red on the outside of his right arm

Been to the different dermatologists and still no of them can pin point this strange rash my 4 year old son has. It is right on the outside of the right elbow and it is like a group of 15 or so white/pinkish small marks in close vicinity to one another, worth stating mother has black pigmentation and father white. Example of the rash is like that of stinging nettles but there is no itch and it has been with him nearly 4 months, or another example is the rash looks like if your child falls and grazes the skin, but this is not the case. There is no other marks or rashes on his body and so far a dermatologist has prescribed a hydro cortisone cream  that doesn't seem to be doing much. Picture attached.

[Bhupinder Kaur, MD]

Hello,
It can be due to vitiligo or idiopathic guttate hypomelanosis. Vitiligo is a pigmentation disorder in which melanocytes (the cells that make pigment) in the skin are destroyed. As a result, white patches appear on the skin in different parts of the body. Diagnosis can be confirmed by external examination, blood tests to check skin cell count for melanocytes and biopsy of the skin patches.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.